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M17 - Tweak Nonce/IV Warning;

This commit is contained in:
lwvmobile 2024-03-06 14:45:26 -05:00
parent d730ca2c25
commit dd87bf77f8
1 changed files with 8 additions and 4 deletions
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12
src/m17.c
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@ -172,10 +172,14 @@ void M17decodeLSF(dsd_state * state)
state->m17_enc = lsf_et;
state->m17_enc_st = lsf_es;
//compare incoming META/IV value on AES, if timestamp 32-bits are not a match (or at least 24 bit, warn user of potential replay/compromise)
uint32_t tsn = (time(NULL) & 0xFFFFFFFF) >> 8; //evaluate 24 bits (within a 255 second window)
uint32_t tsi = (uint32_t)ConvertBitIntoBytes(&state->m17_lsf[112], 24);
if (lsf_et == 2 && tsn != tsi) fprintf (stderr, " \n WARNING! NONCE/IV REPLAY!");
//compare incoming META/IV value on AES, if timestamp 32-bits are not within a time 5 minute window, then throw a warning
uint32_t tsn = (time(NULL) & 0xFFFFFFFF); //current LSB 32-bit value
uint32_t tsi = (uint32_t)ConvertBitIntoBytes(&state->m17_lsf[112], 32); //OTA LSB 32-bit value
uint32_t dif = abs(tsn-tsi);
if (lsf_et == 2 && dif > 3600) fprintf (stderr, " \n Warning! Time Difference > %d secs; Potential NONCE/IV Replay!\n", dif);
//debug
// fprintf (stderr, "TSN: %ld; TSI: %ld; DIF: %ld;", tsn, tsi, dif);
//pack meta bits into 14 bytes
for (i = 0; i < 14; i++)